DAVID MUIR: We turn now to the border, and tonight, the eye-opening message from a leading Senate Republican who was asked if House Republicans should tune out Donald Trump on this. Rachel Scott on the hill.
RACHEL SCOTT: Today, Donald Trump turning up the pressure on Republicans to reject the border security bill their own party has demanded for months. Trump attacking the compromise bill senate Republicans and Democrats are working on together, saying, "Call it the stupid bill. And make sure it doesn't get passed."
DONALD TRUMP: A bad border deal would be worse than no deal at all.
RACHEL SCOTT: Trump wants to kill the bill so he can run on immigration in the general election. But Senate Republican leader Mitch Mcconnell vowing to push forward.
MITCH MCCONNELL: Obviously, this is an incredibly challenging political discussion we've been having. I still favor trying to make law when you can.
SCOTT: Conservative Republican senator James Lankford of Oklahoma, who has been leading the negotiations, tells me Republicans have waiting for this moment for 30 years.
JAMES LANKFORD: Republicans have talked about this for a long time. We've done lots of press conferences. We've done lots of trips to the border. We've done lots of moments to be able to say something needs to be done. This is our "Something" moment.
SCOTT: And to Republicans- to Republicans that are watching what the former president is saying, calling it a betrayal, calling it a stupid bill, are you just telling them to tune that out?
LANKFORD: No, I'm just telling them to read the bill and make their own decision on it.
SCOTT: Donald Trump has called the Senate bill “ridiculous”, insisting it will only make things worse. But here's the thing. Nobody even knows what's in that compromise yet. It is still being negotiated, David.
MUIR: Not even made public yet. Rachel Scott, live on The Hill. Rachel, thank you.